Common as rudder lift line guides on modern Confluence brand kayaks; Perception, Dagger and Wilderness Systems. 1 1/8 inch diameter, takes a single flat head screw, two wide openings on each side. (alt pn 3455-0099)
Learn more, use this text link: Confluence Rudder Install Video part 1 (rudder mount, lift line, foot braces and control cables)
